Aims: Rapid over-activation of β-adrenergic receptor (β-AR) upon stress leads to cardiac inflammation, a prevailing factor that underlies heart injury. However, mechanisms by which acute β-AR stimulation induce cardiac inflammation still remain unknown. Here, we set out to identify the crucial role of inflammasome/interleukin (IL)-18 in initiating and maintaining cardiac inflammatory cascades upon β-AR insult.
View Article and Find Full Text PDFInhibition of matrix metalloproteinases-2 (MMP-2) activation renders cardioprotection from ischemia/reperfusion (I/R) injury; however, the signaling pathways involved have not been fully understood. Intermittent hypobaric hypoxia (IHH) has been shown to enhance myocardial tolerance to I/R injury via triggering intrinsic adaptive responses. Here we investigated whether IHH protects the heart against I/R injury via the regulation of MMP-2 and how the MMP-2 is regulated.
View Article and Find Full Text PDFClin Exp Pharmacol Physiol
January 2014
1. Chronic injection with the β-adrenoceptor (β-AR) agonist isoproterenol (ISO) has been commonly used as an animal model of β-AR-induced cardiac remodelling and heart failure. This ISO-treated model usually exhibits significantly decreased conscious heart rate (HR).
View Article and Find Full Text PDF1. The mouse is the preferred species for gene targeting as a tool for research into the heart and heart development. The developmental features of the geometry and function of the heart in young mice are not well defined and cardiac functional responses following stimulation of beta-adrenoceptors have not been investigated.
View Article and Find Full Text PDFBackground And Purpose: Inflammatory response and cytokine activation are markedly stimulated after myocardial infarction, and contribute to cardiac remodelling. Interleukin-6 (IL-6), a pro-inflammatory cytokine, has pleiotropic effects on cardiac remodelling. Adenosine, released by all cell types, binds to a class of G protein-coupled receptors to induce various cardiovascular effects.
View Article and Find Full Text PDF1. Insulin-like growth factor (IGF)-I plays an important role in the pathogenesis of heart disease and has been shown to strongly induce the proliferation of cardiac fibroblasts (CFs). It remains unknown whether 14-3-3 proteins, which are associated the regulation of signal transduction, affect IGF-I-induced CF proliferation.
View Article and Find Full Text PDFExtracts from the roots and rhizomes of black cohosh (Cimicifuga racemosa) are widely used as dietary supplements to alleviate menopausal symptoms. State-of-the-art quality control measures involve phytochemical fingerprinting of the triterpene glycosides for species identification and chemical standardization by HPLC. In the course of developing materials and methods for standardization procedures, the major C.
View Article and Find Full Text PDFTo test the hypothesis that AMP-activated protein kinase (AMPK) is possibly the downstream signaling molecule of certain subtypes of adrenergic receptor (AR) in the heart, we evaluated AMPK activation mediated by ARs in H9C2 cells, a rat cardiac source cell line, and rat hearts. The AMPK-alpha subunit and the phosphorylation level of Thr(172)-AMPK-alpha subunit were subjected to Western blot analysis. Osmotic minipumps filled with norepinephrine (NE), phenylephrine (PE) or vehicle [0.
View Article and Find Full Text PDFWe previously reported that cardiac fibroblasts, but not cardiomyocytes, are served as the predominant source of IL-6 after isoproterenol stimulation in mouse myocardium. The present study investigated the molecular mechanism of isoproterenol-mediated secretion of IL-6 in mouse cardiac fibroblasts. Treatment of cells with isoproterenol-induced a time-dependent accumulation of IL-6, which was mediated by beta(2)-adrenergic receptor (AR), the preponderant beta-AR subtype in cardiac fibroblasts.
View Article and Find Full Text PDFBiochem Biophys Res Commun
December 2005
Though known as a sensor of energy balance, AMP-activated protein kinase (AMPK) was recently shown to limit damage and apoptotic activity and contribute to the late preconditioning in heart. Interleukin-6 was also reported to involve in anti-apoptosis and cardio-protection in myocardium. Interestingly, both AMPK activity and IL-6 level were increased in response to ischemia, hypertrophy and oxidative stress.
View Article and Find Full Text PDFThe aim of the present study was to investigate the effects of beta-adrenergic receptor (beta-AR) activation on metabolism in cultured neonatal rat cardiomyocytes. The protein synthesis and total protein content of cardiomyocytes were determined by [(3)H]-leucine incorporation and BCA protein content assay. Cardiomyocyte glucose uptake was measured by [(3)H]-2-deoxy-D-glucose uptake analysis.
View Article and Find Full Text PDFBackground: Ginger root (Zingiber officinale) has been used traditionally for the treatment of gastrointestinal ailments such as motion sickness, dyspepsia and hyperemesis gravidarum, and is also reported to have chemopreventative activity in animal models. The gingerols are a group of structurally related polyphenolic compounds isolated from ginger and known to be the active constituents. Since Helicobacter pylori (HP) is the primary etiological agent associated with dyspepsia, peptic ulcer disease and the development of gastric and colon cancer, the anti-HP effects of ginger and its constituents were tested in vitro.
View Article and Find Full Text PDFThe expression of beta-adrenergic receptor subtypes and its effect on neonatal rat cardiac fibroblast proliferation were investigated by radioligand binding assay and [(3)H]-thymidine incorporation analysis, respectively. The results indicated that there was no significant difference in the beta-adrenergic receptor density (B(max)) and affinity (K(D)) between cardiomyocytes and cardiac fibroblasts. The [(125)I]-pindolol competitive inhibition curves (ICI 118551 and CGP 20712A) were significantly better fit in a one-site model in membrane preparation of cardiac fibroblasts.
View Article and Find Full Text PDFAim: To study the functional alpha1-adrenergic receptor (alpha1-AR) subtypes in human right gastroepiploic artery (RGA).
Methods: The effects of alpha2-AR, alpha1-AR, and alpha1-AR subtype selective antagonists on norepinephrine (NE)-induced vasoconstriction in isolated human RGA were observed by contractile function experiment.
Results: Cumulative concentration-response curves for NE were competitively antagonized in RGA by alpha2-AR selective antagonist yohimbine (pA2 6.
The roots/rhizomes of Cimicifuga racemosa L. (Nutt.) (black cohosh) have traditionally been used to treat menopausal symptoms through an unknown mechanism of action.
View Article and Find Full Text PDFEight new and 13 known triterpene glycosides, along with the known compounds glyceryl-1-palmitate and daucosterol-6'-linoleate were isolated from the roots/rhizomes of Cimicifuga racemosa. The new compounds, designated as cimiracemosides I-P (1, 3-9), were determined by spectral analysis to be 7-dehydro-23-epi-12,26-dideoxyacteol-3-O-beta-D-xylopyranoside (1), 12-O-acetyl-25-anhydrocimigenol-3-O-alpha-L-arabinopyranoside (3), 12-O-acetyl-25-anhydrocimigenol-3-O-beta-D-xylopyranoside (4), 4',23-O-diacetylshengmanol-3-O-beta-D-xylopyranoside (5), 4',23-O-diacetylshengmanol-3-O-alpha-L-arabinopyranoside (6), 23-epi-acetylacteol-3-O-alpha-L-arabinopyranoside (7), 4'-O-acetyl-26-deoxyactein (8), and 16beta:23;24:25-diepoxy-12beta-O-acetyl-3beta-hydroxy-9,19-cyclolanost-23,26-olide-O- beta-D-xylopyranoside (9).
View Article and Find Full Text PDFFour phenylpropanoid esters, cimiracemates A-D (1-4), along with three known compounds, isoferulic acid, ferulic acid and methyl caffeate were isolated from the EtOAc fraction of the rhizome of Cimicifuga racemosa. The structures of the esters were elucidated by means of spectral data, including 2D NMR spectroscopy.
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